Diabetes is a general term for disorders in man having excessive urine excretion as in diabetes mellitus and diabetes insipidus. Diabetes mellitus is a metabolic disorder in which the ability to utilize glucose is more or less completely lost. About 2% of all people suffer from diabetes.
Since the introduction of insulin in the 1920's, continuous strides have been made to improve the treatment of diabetes mellitus. To help avoid extreme glycemia levels, diabetic patients often practice multiple injection therapy, whereby insulin is administered with each meal.
Insulin is usually administrated by s.c. or i.m. injections. However, due to the adherent discomfort of injections alternative ways of administration such as nasal and pulmonary has been extensively investigated. For a review on alternative routes of administration of insulin, see Danielsen et al. New routes and means of insulin delivery, in: Childhood and Adolescent Diabetes (Ed. Kelnar), Chapman & Hall Medical, London 1994, pp. 571-584.
In order to circumvent injections, administration of insulin via the pulmonary route could be an alternative way to provide absorption profiles which mimic the endogenous insulin without the need to inject the insulin.